ABB Bailey IEMMU21 Module Mounting Unit – Product Specifications & Technical Overview

The ABB Bailey IEMMU21 is a high‐performance module mounting unit (rack / chassis) designed to house and support ABB Bailey INFI 90 system modules. It provides mechanical stability, electrical connectivity, and high‐reliability backplane communication essential for distributed control system (DCS) operations. Engineered to meet demanding industrial standards, the IEMMU21 ensures secure module installation, long-term durability, and stable operation in critical automation environments.

With robust construction, optimized electrical design, and seamless INFI 90 compatibility, the IEMMU21 is widely used in power plants, chemical facilities, petroleum systems, steel mills, water treatment plants, and large-scale manufacturing automation.

1. Product Overview

The IEMMU21 serves as a rack / cage / mounting unit that houses multiple Bailey INFI 90 system modules. It distributes power, ensures reliable communication between cards through the system backplane, and provides the structural foundation for complete DCS configurations.

It is designed for fast installation, efficient wiring, and long-term stability, making it a key component for building or expanding an ABB Bailey control system.

2. Key Features

• Houses multiple ABB Bailey modules

• Integrated backplane for power distribution and communication

• Robust industrial chassis for stable long-term operation

• High vibration resistance suitable for heavy industrial environments

• Optimized airflow for thermal management

• Standardized mounting dimensions for easy enclosure integration

• Designed for rapid installation & maintenance

• Full compatibility with INFI 90 and Bailey system components

3. Technical Specifications

3.1 General Specifications

• Model: IEMMU21

• Product Type: Module Mounting Unit / Rack Assembly

• System Compatibility: ABB Bailey INFI 90 and Net90

• Purpose:

  • Houses system modules

  • Provides backplane communication

  • Distributes power to installed modules

• Material: Industrial-grade metal chassis

3.2 Backplane Specifications

• Backplane Type: INFI 90 standard communication backplane

• Connections:

  • Power distribution lines

  • Module-to-module communication bus

  • Signal routing pathways

• Connector Type: Rugged edge connectors for reliable contact

• Electrical Protection:

  • Short-circuit protection

  • Surge-resistant bus design

  • EMI/EMC shielding

3.3 Mechanical Specifications

• Frame Structure: Reinforced industrial chassis

• Module Slots: Multiple slots for ABB Bailey system modules

• Mounting Pattern: Standardized for cabinet or rack installation

• Cooling Design:

  • Enhanced airflow openings

  • Passive ventilation for stable operation

• Durability: Built to withstand high vibration and mechanical stress

3.4 Environmental Specifications

• Operating Temperature: Suitable for typical industrial temperature ranges

• Storage Temperature: Long-term storage compatible

• Humidity: Non-condensing industrial humidity levels

• Shock & Vibration: Meets industrial mechanical resilience requirements

3.5 Installation & Operational Features

• Hot-swappable Support: Modules can be inserted/removed without powering down the entire system

• LED Indicators: System power or status indicators depending on configurations

• Cable Management: Efficient routing space for signal and power cables

• Easy Maintenance: Front access for installation and field replacement

4. Functional Description

The IEMMU21 is the foundation of a Bailey controller assembly. It ensures:

• Stable mechanical support for all modules

• Reliable backplane communication between cards

• Consistent power delivery across modules

• Simplified system expansion and upgrading

• Centralized structural integration for control systems

It is essential for building DCS architectures that require high reliability and continuous operation.

5. Typical Industrial Applications

The IEMMU21 is widely used in:

• Power Generation (Coal, Gas, Hydro, Nuclear)

• Petrochemical and Refining Plants

• Oil & Gas Processing Facilities

• Steel & Metallurgy Systems

• Pulp & Paper Production

• Water Treatment & Pumping Stations

• Process Manufacturing & Automation Lines

Its rugged construction and stable backplane design make it suitable for harsh automation environments.

6. User Benefits

• Improved system reliability through stable mechanical and electrical design

• Simplifies DCS expansion with modular integration

• Reduces downtime thanks to fast module replacement

• Long operational lifespan in industrial settings

• Optimized internal wiring and connectivity

• Ensures clean and reliable signal communication